Eye blinking method?
Use Control-R Loop to Loop Cut and Slide one or two more concentric rings for greater control.  More concentric rings reinforce the closed configuration of your eye.

Then select 3 edge rings on edge of eye and

Keyboard Shift E ...Edge Crease ... pull mouse to value 1.

The outside edge is smoothed by Subdivision Surface.

The eye edge is not smooth so vertices can be brought together.

Notice the pink edges of the edges with .... Edge Crease